/*	$OpenBSD: ls.c,v 1.54 2020/10/07 21:03:09 millert Exp $	*/
/*	$NetBSD: ls.c,v 1.18 1996/07/09 09:16:29 mycroft Exp $	*/

/*
 * Copyright (c) 1989, 1993, 1994
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Michael Fischbein.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/types.h>
#include <sys/stat.h>
#include <sys/ioctl.h>

#include <dirent.h>
#include <err.h>
#include <errno.h>
#include <fts.h>
#include <grp.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <limits.h>
#include <locale.h>
#include <util.h>

#include "ls.h"
#include "extern.h"

#include "compat.h"

static void display(FTSENT *, FTSENT *);
static int mastercmp(const FTSENT **, const FTSENT **);
static void traverse(int, char **, int);

static void (*printfcn)(DISPLAY *);
static int (*sortfcn)(const FTSENT *, const FTSENT *);

#define BY_NAME 0
#define BY_SIZE 1
#define BY_TIME 2

long blocksize; /* block size units */
int termwidth;  /* default terminal width */
int sortkey = BY_NAME;

/* flags */
int f_accesstime;   /* use time of last access */
int f_column;       /* columnated format */
int f_columnacross; /* columnated format, sorted across */
int f_flags;        /* show flags associated with a file */
int f_grouponly;    /* long listing format without owner */
int f_humanval;     /* show human-readable file sizes */
int f_inode;        /* print inode */
int f_listdir;      /* list actual directory, not contents */
int f_listdot;      /* list files beginning with . */
int f_longform;     /* long listing format */
int f_nonprint;     /* show unprintables as ? */
int f_nosort;       /* don't sort output */
int f_numericonly;  /* don't expand uid to symbolic name */
int f_recursive;    /* ls subdirectories also */
int f_reversesort;  /* reverse whatever sort is used */
int f_sectime;      /* print the real time for all files */
int f_singlecol;    /* use single column output */
int f_size;         /* list size in short listing */
int f_statustime;   /* use time of last mode change */
int f_stream;       /* stream format */
int f_type;         /* add type character for non-regular files */
int f_typedir;      /* add type character for directories */

int rval;

int main(int argc, char *argv[]) {
  setprogname(argv[0]);
  static char dot[] = ".", *dotav[] = {dot, NULL};
  struct winsize win;
  int ch, fts_options, notused;
  int kflag = 0;
  char *p;

#ifndef SMALL
  setlocale(LC_CTYPE, "");
#endif

  /* Terminal defaults to -Cq, non-terminal defaults to -1. */
  if (isatty(STDOUT_FILENO)) {
    f_column = f_nonprint = 1;
  } else {
    f_singlecol = 1;
  }

  termwidth = 0;
  if ((p = getenv("COLUMNS")) != NULL && *p != '\0')
    termwidth = strtoll(p, NULL, 10);
  if (termwidth == 0 && ioctl(STDOUT_FILENO, TIOCGWINSZ, &win) == 0 &&
      win.ws_col > 0)
    termwidth = win.ws_col;
  if (termwidth == 0)
    termwidth = 80;

  /* Root is -A automatically. */
  if (!getuid())
    f_listdot = 1;

  fts_options = FTS_PHYSICAL;
  while ((ch = getopt(argc, argv, "1ACFHLRSTacdfghiklmnpqrstux")) != -1) {
    switch (ch) {
    /*
     * The -1, -C and -l, -m, -n and -x options all override each
     * other so shell aliasing works right.
     */
    case '1':
      f_singlecol = 1;
      f_column = f_columnacross = f_longform = 0;
      f_numericonly = f_stream = 0;
      break;
    case 'C':
      f_column = 1;
      f_columnacross = f_longform = f_numericonly = 0;
      f_singlecol = f_stream = 0;
      break;
    case 'g':
      f_longform = 1;
      if (f_grouponly != -1)
        f_grouponly = 1;
      f_column = f_columnacross = f_singlecol = f_stream = 0;
      break;
    case 'l':
      f_longform = 1;
      f_grouponly = -1; /* -l always overrides -g */
      f_column = f_columnacross = f_singlecol = f_stream = 0;
      break;
    case 'm':
      f_stream = 1;
      f_column = f_columnacross = f_longform = 0;
      f_numericonly = f_singlecol = 0;
      break;
    case 'x':
      f_columnacross = 1;
      f_column = f_longform = f_numericonly = 0;
      f_singlecol = f_stream = 0;
      break;
    case 'n':
      f_longform = 1;
      f_numericonly = 1;
      f_column = f_columnacross = f_singlecol = f_stream = 0;
      break;
    /* The -c and -u options override each other. */
    case 'c':
      f_statustime = 1;
      f_accesstime = 0;
      break;
    case 'u':
      f_accesstime = 1;
      f_statustime = 0;
      break;
    case 'F':
      f_type = 1;
      break;
    case 'H':
      fts_options |= FTS_COMFOLLOW;
      break;
    case 'L':
      fts_options &= ~FTS_PHYSICAL;
      fts_options |= FTS_LOGICAL;
      break;
    case 'R':
      f_recursive = 1;
      break;
    case 'f':
      f_nosort = 1;
      /* FALLTHROUGH */
    case 'a':
      fts_options |= FTS_SEEDOT;
      /* FALLTHROUGH */
    case 'A':
      f_listdot = 1;
      break;
    /* The -d option turns off the -R option. */
    case 'd':
      f_listdir = 1;
      f_recursive = 0;
      break;
    case 'h':
      f_humanval = 1;
      break;
    case 'i':
      f_inode = 1;
      break;
    case 'k':
      blocksize = 1024;
      kflag = 1;
      break;
    case 'p':
      f_typedir = 1;
      break;
    case 'q':
      f_nonprint = 1;
      break;
    case 'r':
      f_reversesort = 1;
      break;
    case 'S':
      sortkey = BY_SIZE;
      break;
    case 's':
      f_size = 1;
      break;
    case 'T':
      f_sectime = 1;
      break;
    case 't':
      sortkey = BY_TIME;
      break;
    default:
      usage();
    }
  }
  argc -= optind;
  argv += optind;

  /*
   * If both -g and -l options, let -l take precedence.
   * This preserves compatibility with the historic BSD ls -lg.
   */
  if (f_grouponly == -1)
    f_grouponly = 0;

  /*
   * If not -F, -i, -l, -p, -S, -s or -t options, don't require stat
   * information.
   */
  if (!f_longform && !f_inode && !f_size && !f_type && !f_typedir &&
      sortkey == BY_NAME)
    fts_options |= FTS_NOSTAT;

  /*
   * If not -F, -d or -l options, follow any symbolic links listed on
   * the command line.
   */
  if (!f_longform && !f_listdir && !f_type)
    fts_options |= FTS_COMFOLLOW;

  /* If -l or -s, figure out block size. */
  if (f_longform || f_size) {
    if (!kflag)
      (void)getbsize(&notused, &blocksize);
    blocksize /= 512;
  }

  /* Select a sort function. */
  if (f_reversesort) {
    switch (sortkey) {
    case BY_NAME:
      sortfcn = revnamecmp;
      break;
    case BY_SIZE:
      sortfcn = revsizecmp;
      break;
    case BY_TIME:
      if (f_accesstime)
        sortfcn = revacccmp;
      else if (f_statustime)
        sortfcn = revstatcmp;
      else /* Use modification time. */
        sortfcn = revmodcmp;
      break;
    }
  } else {
    switch (sortkey) {
    case BY_NAME:
      sortfcn = namecmp;
      break;
    case BY_SIZE:
      sortfcn = sizecmp;
      break;
    case BY_TIME:
      if (f_accesstime)
        sortfcn = acccmp;
      else if (f_statustime)
        sortfcn = statcmp;
      else /* Use modification time. */
        sortfcn = modcmp;
      break;
    }
  }

  /* Select a print function. */
  if (f_singlecol)
    printfcn = printscol;
  else if (f_columnacross)
    printfcn = printacol;
  else if (f_longform)
    printfcn = printlong;
  else if (f_stream)
    printfcn = printstream;
  else
    printfcn = printcol;

  if (argc)
    traverse(argc, argv, fts_options);
  else
    traverse(1, dotav, fts_options);
  return (rval);
}

static int output; /* If anything output. */

/*
 * Traverse() walks the logical directory structure specified by the argv list
 * in the order specified by the mastercmp() comparison function.  During the
 * traversal it passes linked lists of structures to display() which represent
 * a superset (may be exact set) of the files to be displayed.
 */
static void traverse(int argc, char *argv[], int options) {
  FTS *ftsp;
  FTSENT *p, *chp;
  int ch_options, saved_errno;

  if ((ftsp = fts_open(argv, options, f_nosort ? NULL : mastercmp)) == NULL)
    err(1, NULL);

  /*
   * We ignore errors from fts_children here since they will be
   * replicated and signalled on the next call to fts_read() below.
   */
  chp = fts_children(ftsp, 0);
  if (chp != NULL)
    display(NULL, chp);
  if (f_listdir)
    return;

  /*
   * If not recursing down this tree and don't need stat info, just get
   * the names.
   */
  ch_options = !f_recursive && options & FTS_NOSTAT ? FTS_NAMEONLY : 0;

  while ((p = fts_read(ftsp)) != NULL)
    switch (p->fts_info) {
    case FTS_D:
      if (p->fts_name[0] == '.' && p->fts_level != FTS_ROOTLEVEL &&
          !f_listdot) {
        (void)fts_set(ftsp, p, FTS_SKIP);
        break;
      }

      /*
       * If already output something, put out a newline as
       * a separator.  If multiple arguments, precede each
       * directory with its name.
       */
      if (output)
        (void)printf("\n%s:\n", p->fts_path);
      else if (f_recursive || argc > 1) {
        (void)printf("%s:\n", p->fts_path);
        output = 1;
      }

      chp = fts_children(ftsp, ch_options);
      saved_errno = errno;
      display(p, chp);

      /*
       * On fts_children() returning error do recurse to see
       * the error.
       */
      if (!f_recursive && !(chp == NULL && saved_errno != 0))
        (void)fts_set(ftsp, p, FTS_SKIP);
      break;
    case FTS_DC:
      warnx("%s: directory causes a cycle", p->fts_name);
      break;
    case FTS_DNR:
    case FTS_ERR:
      warnx("%s: %s", p->fts_name[0] == '\0' ? p->fts_path : p->fts_name,
            strerror(p->fts_errno));
      rval = 1;
      break;
    }
  if (errno)
    err(1, "fts_read");

  fts_close(ftsp);
}

/*
 * Display() takes a linked list of FTSENT structures and passes the list
 * along with any other necessary information to the print function.  P
 * points to the parent directory of the display list.
 */
static void display(FTSENT *p, FTSENT *list) {
  struct stat *sp;
  DISPLAY d;
  FTSENT *cur;
  NAMES *np;
  off_t maxsize;
  nlink_t maxnlink;
  unsigned long long btotal;
  blkcnt_t maxblock;
  ino_t maxinode;
  int bcfile, flen, glen, ulen, maxflags, maxgroup, maxuser, maxlen;
  int entries, needstats;
  int width;
  const char *user, *group;
  char nuser[12], ngroup[12];
  char buf[21]; /* 64 bits == 20 digits */
  char *flags = NULL;

  needstats = f_inode || f_longform || f_size;
  flen = 0;
  btotal = maxblock = maxinode = maxlen = maxnlink = 0;
  bcfile = 0;
  maxuser = maxgroup = maxflags = 0;
  maxsize = 0;
  for (cur = list, entries = 0; cur != NULL; cur = cur->fts_link) {
    if (cur->fts_info == FTS_ERR || cur->fts_info == FTS_NS) {
      warnx("%s: %s", cur->fts_name, strerror(cur->fts_errno));
      cur->fts_number = NO_PRINT;
      rval = 1;
      continue;
    }

    /*
     * P is NULL if list is the argv list, to which different rules
     * apply.
     */
    if (p == NULL) {
      /* Directories will be displayed later. */
      if (cur->fts_info == FTS_D && !f_listdir) {
        cur->fts_number = NO_PRINT;
        continue;
      }
    } else {
      /* Only display dot file if -a/-A set. */
      if (cur->fts_name[0] == '.' && !f_listdot) {
        cur->fts_number = NO_PRINT;
        continue;
      }
    }
    if ((width = mbsprint(cur->fts_name, 0)) > maxlen)
      maxlen = width;
    if (needstats) {
      sp = cur->fts_statp;
      if (sp->st_blocks > maxblock)
        maxblock = sp->st_blocks;
      if (sp->st_ino > maxinode)
        maxinode = sp->st_ino;
      if (sp->st_nlink > maxnlink)
        maxnlink = sp->st_nlink;
      if (sp->st_size > maxsize)
        maxsize = sp->st_size;

      btotal += sp->st_blocks;
      if (f_longform) {
        if (f_numericonly) {
          snprintf(nuser, sizeof nuser, "%u", sp->st_uid);
          snprintf(ngroup, sizeof nuser, "%u", sp->st_gid);
          user = nuser;
          group = ngroup;
        } else {
          user = user_from_uid(sp->st_uid, 0);
          group = group_from_gid(sp->st_gid, 0);
        }
        if ((ulen = strlen(user)) > maxuser)
          maxuser = ulen;
        if ((glen = strlen(group)) > maxgroup)
          maxgroup = glen;
        flen = 0;

        if ((np = malloc(sizeof(NAMES) + ulen + 1 + glen + 1 + flen + 1)) ==
            NULL)
          err(1, NULL);

        np->user = &np->data[0];
        (void)strlcpy(np->user, user, ulen + 1);
        np->group = &np->data[ulen + 1];
        (void)strlcpy(np->group, group, glen + 1);

        if (S_ISCHR(sp->st_mode) || S_ISBLK(sp->st_mode))
          bcfile = 1;

        if (f_flags) {
          np->flags = &np->data[ulen + 1 + glen + 1];
          (void)strlcpy(np->flags, flags, flen + 1);
          if (*flags != '-')
            free(flags);
        }
        cur->fts_pointer = np;
      }
    }
    ++entries;
  }

  /*
   * If there are no entries to display, we normally stop right
   * here.  However, we must continue if we have to display the
   * total block count.  In this case, we display the total only
   * on the second (p != NULL) pass.
   */
  if (!entries && (!(f_longform || f_size) || p == NULL))
    return;

  d.list = list;
  d.entries = entries;
  d.maxlen = maxlen;
  if (needstats) {
    d.bcfile = bcfile;
    d.btotal = btotal;
    (void)snprintf(buf, sizeof(buf), "%llu", (unsigned long long)maxblock);
    d.s_block = strlen(buf);
    d.s_flags = maxflags;
    d.s_group = maxgroup;
    (void)snprintf(buf, sizeof(buf), "%llu", (unsigned long long)maxinode);
    d.s_inode = strlen(buf);
    (void)snprintf(buf, sizeof(buf), "%lu", (unsigned long)maxnlink);
    d.s_nlink = strlen(buf);
    if (!f_humanval) {
      (void)snprintf(buf, sizeof(buf), "%lld", (long long)maxsize);
      d.s_size = strlen(buf);
    } else
      d.s_size = FMT_SCALED_STRSIZE - 2; /* no - or '\0' */
    d.s_user = maxuser;
  }

  printfcn(&d);
  output = 1;

  if (f_longform)
    for (cur = list; cur != NULL; cur = cur->fts_link)
      free(cur->fts_pointer);
}

/*
 * Ordering for mastercmp:
 * If ordering the argv (fts_level = FTS_ROOTLEVEL) return non-directories
 * as larger than directories.  Within either group, use the sort function.
 * All other levels use the sort function.  Error entries remain unsorted.
 */
static int mastercmp(const FTSENT **a, const FTSENT **b) {
  int a_info, b_info;

  a_info = (*a)->fts_info;
  if (a_info == FTS_ERR)
    return (0);
  b_info = (*b)->fts_info;
  if (b_info == FTS_ERR)
    return (0);

  if (a_info == FTS_NS || b_info == FTS_NS) {
    if (b_info != FTS_NS)
      return (1);
    else if (a_info != FTS_NS)
      return (-1);
    else
      return (namecmp(*a, *b));
  }

  if (a_info != b_info && (*a)->fts_level == FTS_ROOTLEVEL && !f_listdir) {
    if (a_info == FTS_D)
      return (1);
    if (b_info == FTS_D)
      return (-1);
  }
  return (sortfcn(*a, *b));
}
